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March 8, 1932. w. w. HARTMAN TOOL FOR PLACING AND REMOVING PISTON PINS Filed Oct. 26, 1928 [WE/V7017 MIL/ml Mfl'hfrya/Y I w i w mm mm .5 8

wvNO w \N v m\ m 3 t3 $w Q A? Patented Mar. 8, 1932' UNITED STATES WILLIAM W. HARTMAN, OF MEMPHIS, TENNESSEE TOOL FOR PLACING AN D REMOVING PISTON PINS Application filed October 26, 1928. Serial No. 315,290.

This invention relates to improvements in tools for removing and replacing piston pins and has especial relation to a tool for removing or replacing the hollow pins of automobile engine pistons.

Automobiles of the present dayare largely provided with hollow piston pins, of which of course owing to quantity production, tremendous numbers of any one size are in use.

It is therefore economically feasible to provide a tool for placing and removing these pins.

Previously it has been hard to remove a pin without damaging the end thereof or scarring the pin bearing, and also it has been hard to placea pin in the piston without at times breaking the retaining ring which holds the pin in place, and this tool is designed to eliminate these troubles.

The objects of this invention are:

(a) To provide a tool, on which the pin may be placed and bywhich it will be securely held without damage to the ends of the pin; through the medium of which tool the retaining ring may be expanded to per- 3 mit placing of the pin and by means of which tool the ends of the pin may be protected when the pin is being disengaged from the retaining ring and removed from the piston;

(b) To provide a tool of this character 3 which may be adjusted to varying lengths of pin; and

(0) To generally improve the design and constructionof such a tool.

The means by which these and other objects are accomplished and the manner of their accomplishment, will readily be understood from the followingspecification, on reference to the accompanying drawings in which Fig. 1 is a sectional elevation through an automobile piston, piston pin, and the piston end of the connecting rod, with the tool for placing and removing the pinin place as it would appear at the completion of placing a pin, or just before starting to remove the pin.

Fi 2 is an enlarged fragmentary detail showing the shape of the undercut shoulder on the tool and the manner in which it engages and protects the end of the pin.

Referring now to the drawings in which the various parts are indicated by numerals;

the pin,

- 2, to receive the end of the piston pin. It

10 is the piston, 11 the piston end of the connecting rod, 12 a hollow cylindrical piston pin in place in the piston, and 13 the pin retaining ring. 14 is a shallow annular groove in the exterior of the pin in which groove the ,55 split ring 13 seats, and 15" an auxiliary annular groove in the interior of the connecting rod end, into which groove the ring 13 may be expanded to allow placing or removing of The. pin removing and replacing tool comprises two parts, 16 and 16A respectively, one of wh1ch parts is interiorly threaded to receive a projecting threaded end 17 on the other part. The part 16 is provided with a cylindrical body portion 18, slightly less in diameter than the diameter of the pin with which it is to be used whereby such part will readily enter and slide within the hole bored in the piston for the reception of the pin, and is further provided with a handle portion 19, preferably of the same diameter, which handle .portion is preferably knurled to provide a hand grip. Adjacent the body portion 18 is ashort or collar portion 20 of reduced area, which is a loose fit in the interior of the piston pin. Where the body and collar portion 18 and 20 join, the shoulder 21 thus formed is slightly undercut as shown in detail in Fig.

will be noted that the exterior of the pin end is coned, giving a beveled portion 22, be-

I tween the exterior cylindrical surface of the pin and the flat end part 23, and that this beveled portion of the pin end is engaged by the undercut shoulder of the tool, so that all danger of damaging such end is obviated.

The opposite pin part 16A is similarly formed, with a cylindrical body portion 24 of slightly less diameter than the piston pin, a collar portion 25 loosely fitting the interior of the pin and with the shoulder- 26 thus formed slightly undercut as in the preceding P v Integral with and pro ecting from the collar portion 25 is a center portion 27 of smaller diameter than the collar portions, and 1 from this centralportion the threaded end 17 projects. Extending from the body porin placethe tapered end 28 of the tool is slid into the piston pin hole until the conical surface engages the retaining ring 13, which has previously been placed in the connecting rod end. This ring is expanded into the groove 15 as the tool is further pushed in, and is further slightly expanded by the pin itself, on which it thereafter rides until the groove 14 in the pin is reached. At this point which is the position the pin should occupy further progress is checked by the ring, and unless extra force be exerted the pin will there remain. The parts 16 and 16A are then unscrewed and removed, leaving the pin in such position.

To remove a pin, the parts 16 and 16A are unscrewed, and as before assembled with the collars 20 and 25 within the pin, and thereafter tightened to firmly seat the shoulders 21 and 26 against the ends of the pin. The

pin is then driven out by tapping with a hammer on either end of the tool, preferably on the tapered end 28, causing the ring 13 to ride up one of the flat sides of the groove 14: into the relieving groove 15, thus permittingthe pin1 to be driven out and removed with the too It will be noted that in placing the pin the tapered end of the tool expands the retaining ring very gently thus minimizing danger of jamming the ring and breaking it, and also, in either placing. or removing the pin, that the supporting of the pin by the collars and the clamping of the pin against the undercut shoulders of the tool minimizes danger of scarring or otherwise damaging the ends of the pin.

It will also be noted that the central portion 27 does not butt against the collar 20 and that therefore pins having considerable variation in length may be handled with one tool.

Having described my invention, what I claim is: y

l. A tool for removing and replacing hollow piston-pins, comprising two parts; each having a cylindrical body of slightly less diameter than the exterior diameter of the pin, and adjacent collar portions approximately fitting the interior of the pin, each of the shoulders thus formed being slightly undercut; one of said parts having a tapered portion extending from said body portion away from said collar portion, and the other of said parts having a handle portion similarly extending from said body portion; a central portion of less diameter than said collar portions extending from one of said collar portions and an externally threaded end extending from the end of said central portion, the other of said collar portions being interiorly threaded to permit engagement of said externally threaded portion therewith, whereby said parts may be engaged together to support and clamp a hollow pin therebetween.

2. A tool for removing and replacing hollow piston-pins, comprising two parts; each having a cylindrical body of slightly less diameter than the exterior diameter of the pin and adjacent collar portions approximately fitting the interior of the pin; one of said parts having a tapered portion extendlng from said body portion away from said collar portion, and the other of said parts having a handle portion similarly extending from said body portion; a central portion of less diameter than said collar portions extending from one of said collar portions and an externally threaded end extending from the end of said central portion, the other of said collar portions being interiorly threaded to permit engagement of said externally threaded portion therewith, whereby said parts may be engaged together to support and clamp a hollow pin therebetween.

- 3. A tool for removing and replacing hollow piston-pins, comprising two parts; each having a cylindrical body of slightly less diameter than the exterior diameter of the pin and adjacent collar portions approximately fitting the interior of the pin; one of said parts having a tapered portion extending from said body portion away from said collar portion; a central portion of less diameter than said collar portion extending from one of said collar portions and an externally threaded end extending from the end of said central portion, the other of said collar portions being interiorly threaded to permit engagement of said externally threaded portion therewith, whereby said parts may be engaged together to support and clamp a hollow pin therebetween.

4. A tool for the purpose described, comprising a section having a portion of a size to substantially fit in and be passed endwise through the wrist-pin receiving bore of a piston and also having a taper at the forward end of said portion and an abutment at the rear end thereof and spaced from said taper, and further having in rear of said abutment a portion to enter one end of a tubular wristpin and maintain it with its perimeter sub-' stantially flush with that of the first named section and having an abutment to bear against the rear end of the tubular wrist-pin and hold it against the first named abutment.

5. A tool for the purpose described, comprising a section having a portion of a size to substantially fit in and be passed endwise through the wrist-pin receiving bore of a piston and also having a taper at the forward end of said portion and an abutment at the rear end thereof and spaced from said taper, and further having in rear of said abutment a portion to enter oneend of a tubular wristpin and maintain it with its perimeter substantially flush with that of the first named portion, and a section detachably connected to the first named section and having an abutment to bear against the rear end of the tubular wrist-pin and hold it against the first named abutment.

6. A tool for insertin and removing piston wrist-pins and the 1' e, having a tapered pilot portion at one end of such length as to engage and aline the bearing of a connecting rod with the pin openingof a piston, a pin-engaging portion at the other end, there being a shoulder at the base of said pin-engaging portion, and a cylindrical portion of uniform diameter between said shoulder and the base of said tapered pilot portion, the diameter of said cylindrical portion being slightly less than that of the pin to be inserted or removed.

7. In a pilot for wrist-pins, a pilot structure comprising a frusto-conical end portion diverging to the outside diameter of a wristpin, and an extended and reduced portion axially ali ned with the frusto-conical portion, there being an annular shoulder between the reduced portion and the frusto-conical portion, the shoulder being concave to receive the convex end of a hollow wrist-pin, the extended portion being insertable with in the pin, the structure functioning as an expanding means for a retainer ring positioned in a connecting arm.

8. In a pilot for wrist-pins, a structure of the kind described consisting of an outwardly tapered end portion, and a straight portion at the large end of the ta red portion, and

mate ends of both the forcing and pilot members being peripherally grooved to receive piston pin, the proximate ends of the said members having extensions adapted to pass into the piston pin.

11. A. tool of the character described in cluding a shaft adapted to be inserted through a tubular wrist-pin and driving heads attached to the ends of the shaft, one of said heads being removable, the inner ends of said heads being reduced forming substantially cylindrical extensions formed to fit into the'ends of the pin, and having adj acent external shoulders on the heads ed to abut said ends of said pin. 7

12. A tool for dislodging tubular wristpins including a shaft,a head attached to each end of the shaft, one of said heads being removable, the inner end ofeach head reduced forming an extension to fit into the pin with an external shoulder adjacent said extension to abut thecorresponding end of the pin, each head having an exposed driving surface.

In testimony whereof I hereunto afiix my signature.

WILLIAM W. HARTMAN.

there being a reduced an extended portion axially aligned with the tapered portion and integral therewith, and a shoulder adjacent the connection of the reduced ortion to the straight portion, the shoulder ing concave, all for the purpose described.

9. A tool for applying and removing wristpins comprising a member consisting of a stem having two adjacent substantially cylindrical enlarged portions at one end thereof,

the outer one of said cylindrical portions havlng a diameter greater than the inner one and having a tapered portion extending out therefrom, a shank member having a diameter the same as said larger portion and having a substantially cylindrical reduced end portion with a diameter the same assaid smaller portion, and means for attaching and detaching said stem and shank axially with relation to each other. 10. In a device for installin piston pins, a forcin mem r, a tapere .pilot member, said orcing member and tapered pilot member being adapted to be removably attached to each other, the proxiand removin adapt- 

